microbiology exam 2 review pt. 1

Special considerations must be taken when using bacteria to produce a eukaryotic protein. What is the cause for this additional difficulty? A. Prokaryotic DNA contains different nucleotides. B. Transcription is in prokaryotes is very different from transcription in eukaryotes. C. Translation in prokaryotes is very different from translation in eukaryotes. D. Eukaryotic genes contain introns, which prokaryotic cells cannot remove.

D. Eukaryotic genes contain introns, which prokaryotic cells cannot remove.

Why would a recombinant DNA molecule be inserted into a host cell? A. Plasmids cannot be isolated outside of a host cell. B. Restriction enzymes can only be used inside of a cell. C. It can protect the recombinant DNA D. It can be copied, transcribed, and translated into a desired protein.

D. It can be copied, transcribed, and translated into a desired protein.

Which of these statements is NOT true about DNA replication? A. RNA polymerase synthesizes the primers. B. DNA ligase joins the small DNA fragments of the lagging strand. C. DNA polymerase is required to add new nucleotides to the growing ends of the DNA strands. D. Only one strand of the parent DNA serves as a template for a newly synthesized complementary strand.

D. Only one strand of the parent DNA serves as a template for a newly synthesized complementary strand.

How do the strands separate during PCR? A. The cycling of the temperatures breaks the hydrogen bonds between the two strands. B. The primers separate the strands during the annealing step. C. The DNA polymerase breaks the hydrogen bonds between the two strands. D. The high heat of the denaturation step breaks the hydrogen bonds between the two strands.

D. The high heat of the denaturation step breaks the hydrogen bonds between the two strands.

Consider the polypeptide sequence encoded by the following DNA. 5'TACAAAGAAATT6' If base number 6 is changed to G, how will this affect the polypeptide? A. A frameshift mutation will result. B. A nonsense mutation will result in premature termination of the polypeptide. C. Translation will stop. D. There will be no change in the polypeptide. E. One amino acid will be changed.

D. There will be no change in the polypeptide.

Which of these statements is NOT true of plasmids? A. They are small, circular molecules of DNA that can carry genes for heavy metal resistance. B. They may contain antibiotic resistance genes. C. They can be transferred between bacteria during conjugation. D. They are essential for survival of the organism in most situations. E. They may encode genes that enhance the pathogenicity of an organism.

D. They are essential for survival of the organism in most situations.

In general, how might recombinant DNA technology be used to prevent a genetic disorder caused by a mutation in a single gene? A. To insert a desirable gene B. To remove an undesirable gene C. To replace a defective gene with a working gene D. To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene

D. To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene

Which of the following is a safety issue related to the use of recombinant DNA? A. allergic reactions to components in genetically modified foods B spread of bioengineered traits, such as herbicide resistance, into related weed species C. reduction in populations of "desirable" insects due to the use of Bt insecticide D. all of these

D. all of these

In genetic engineering, antibiotic-resistance genes are usually cloned into vectors to __________. A. select for cells that cannot grow B. kill the recombinant organisms C. select for cells having undergone spontaneous mutation D. allow selection for bacteria containing the vector

D. allow selection for bacteria containing the vector

The process of making multiple copies of a DNA molecule is referred to as __________. A. hybridization B. protoplast fusion C. transformation D. amplification E. biomagnification

D. amplification

If you put the gene for Bt toxin from Bacillus thuringiensis into a tomato plant, the resulting plants will __________. A. die B. be toxic to humans who eat the tomatoes C. have a Bacillus infection D. be toxic to insects that eat them

D. be toxic to insects that eat them

The use of microorganisms, cells, or cell components to make products such as hormones, antibiotics, food, or vaccines is known as __________. A. rDNA technology B. cloning C. genetic engineering D. biotechnology

D. biotechnology

In E. coli, Hfr cells ________. A. fuse with gram-positive cells by way of sticky surface materials B. do not form sex pili C. lack the genes typically carried on the F factor D. can pass main chromosome genes to a recipient cell E. typically pass the entire F factor to F- cells

D. can pass main chromosome genes to a recipient cell

In E. coli, Hfr cells ________. A. fuse with gram-positive cells by way of sticky surface materials B. do not form sex pili C. lack the genes typically carried on the F factor D. can pass main chromosome genes to a recipient cell E. typically pass the entire F factor to F- cells

D. can pass main chromosome genes to a recipient cell

Which of the following requires cell-to-cell contact? A. mutation B. transformation C. transduction D. conjugation

D. conjugation

A plasmid that has been cleaved with EcoRI can recombine with another plasmid that has been __________. A. digested with HindIII B. amplified by PCR C. cleaved with BamHI D. digested with EcoRI

D. digested with EcoRI

Southern blotting is used to __________. A. identify specific proteins B. select for antibiotic-resistant organisms C. identify particular sequences of RNA D. identify particular sequences of DNA

D. identify particular sequences of DNA

Arrange the following steps from a typical genetic modification procedure into their correct sequence. A. Isolate bacterial plasmid B. Protein product harvested from bacteria C. Select gene of interest + insert into plasmid D. Bacteria replicate E. Cloned gene harvested from bacteria F. Plasmid taken up by bacteria

A. Isolate bacterial plasmid C. Select gene of interest + insert into plasmid F. Plasmid taken up by bacteria D. Bacteria replicate E. Cloned gene harvested from bacteria/ B. Protein product harvested from bacteria

The chemical 5-bromouracil is a mutagen because it __________. A. is similar to thymine in structure and base-pairing ability B. inserts between "stacked base pairs," affecting the accuracy of DNA replication C. is similar to uracil in structure and base-pairing ability D. is similar to thymine in structure but not base-pairing ability E. causes thymine-thymine dimers to form

D. is similar to thymine in structure but not base-pairing ability

Using the genetic code in your textbook (Figure 8.8), determine the polypeptide encoded by the RNA sequence 5'AUGUUUCUUUAA3'. A. tyr-lys-glu-ile B. asp-lys-phe C. phe-lys-lys-his D. met-phe-leu

D. met-phe-leu

The major source of the genetic diversity among microorganisms upon which natural selection operates is __________. A. conjugation B. transformation C. transduction D. mutation

D. mutation

In the blue-white screening procedure, bacteria that are transformed with recombinant plasmid and cultured in media containing ampicillin and X-gal will __________. A. not grow in this medium B. grow more rapidly than cells without recombinant DNA C. produce blue colonies D. produce white colonies E. produce the enzyme beta-galactosidase

D. produce white colonies

A frameshift mutation in a gene encoding a protein usually __________. A. results in a single amino acid change upstream from the mutation B. improves the function of the encoded protein C. results in a modified but functional protein D. results in the production of a nonfunctional peptide E. affects the mRNA but not the peptide

D. results in the production of a nonfunctional peptide

A good cloning vector __________. A. should have a high concentration of guanine B. should not be able to be cut by more than one restriction enzyme C. should be readily degraded in the host D. should have a gene or genes that allows for selection of transformed host cells E. should not be capable of replication

D. should have a gene or genes that allows for selection of transformed host cells

In the lac operon of E. coli, ________. A. the gene for beta-galactosidase is regulated independently of a gene for lactose uptake by the cell B. the structural genes cease to be transcribed if allolactose binds to the repressor C. the structural genes for lactose utilization are constitutive D. the operon consists entirely of three structural genes for lactose utilization E. the repressor protein binds to the operator in the absence of lactose

E. the repressor protein binds to the operator in the absence of lactose

Assume a cell is grown in a culture medium containing radioactively labeled thymidine. After three cell divisions, what percentage of the cells would contain the radioactive label? A. 25% B. 30% C. 37.5% D. 87.5% E. 100%

E. 100%

Which of the following correctly describes the lac operon? A. It is an inducible operon that is turned on if lactose is present and glucose is absent. B. It is repressible operon that is turned on in the presence of lactose. C. It is a constitutive operon that is unaffected by the presence of lactose. D. It is an inducible operon that is turned on in the presence of glucose.

A. It is an inducible operon that is turned on if lactose is present and glucose is absent.

Which of the following statements concerning translation is correct? A. The ribosome stops protein synthesis when it reaches a nonsense codon in the mRNA. B. tRNAs enter the ribosome at the E site and leave from the A site. C. Amino acids are brought to the ribosome by the mRNA. D. Each set of three nucleotides in the mRNA is called an anticodon.

A. The ribosome stops protein synthesis when it reaches a nonsense codon in the mRNA.

Which of the following statements in NOT true of plasmids? A. They are essential for survival of the organism in most situations. B. They may encode genes that enhance the pathogenicity of an organism. C. They may contain antibiotic resistance genes. D. They are small, circular molecules of DNA that can carry genes for heavy metal resistance. E. They can be transferred between bacteria during conjugation.

A. They are essential for survival of the organism in most situations.

Which of the following statements is NOT true of base substitutions? A. A base substitution may cause no change in the protein encoded by the affected gene. B. A base substitution can result in the production of a shortened protein. C. A base substitution may be beneficial if the affected gene encodes an enzyme with enhanced activity. D. Base substitutions may be caused by radiation or chemical mutagens. E. Mutations rarely involve base substitutions.

E. Mutations rarely involve base substitutions.

In the lac operon of E. coli, ________. A. the gene for beta-galactosidase is regulated independently of a gene for lactose uptake by the cell B. the structural genes cease to be transcribed if allolactose binds to the repressor C. the structural genes for lactose utilization are constitutive D. the operon consists entirely of three structural genes for lactose utilization E. the repressor protein binds to the operator in the absence of lactose

E. the repressor protein binds to the operator in the absence of lactose

For the amino acid aspartic acid (asp), __________. A. the corresponding tRNA would have the anticodon 3'CTA5' B. the corresponding tRNA would have the anticodon 3'GAC5' C. the sequence of the DNA template would be 3'CAG5' D. the sequence of the DNA template would be 3'GAC5' E. the sequence of the DNA template would be 3'CTG5'

E. the sequence of the DNA template would be 3'CTG5'

Which of the following is NOT a purpose of genetic modification? A. to create multiple copies of a gene of interest B. to create proteins used in vaccines (e.g., hepatitis B vaccine) C. to create hormones such as insulin or human growth hormone D. to modify the characteristics of an organism E. to remove antibiotic resistant plasmids from bacteria

E. to remove antibiotic resistant plasmids from bacteria

During the Southern blotting technique, what is the purpose of transferring the DNA fragments from the gel to a nitrocellulose filter? A. This step attaches the DNA fragments to a permanent substrate, which then can be probed. B. This step prepares the DNA fragments for PCR. C. This step prepares the DNA for digestion by restriction enzymes. D. This step selects and transfers only the genes of interest. E. This step separates the two complementary DNA strands

A. This step attaches the DNA fragments to a permanent substrate, which then can be probed.

TRUE OR FALSE: In E. coli, the presence of lactose is necessary and sufficient for expression of the lactose-utilization genes.

False

TRUE OR FALSE: Mutations are always harmful to cells.

False

TRUE OR FALSE: Real-time PCR differs from traditional PCR in that real-time PCR amplification is monitored by gel electrophoresis.

False

TRUE OR FALSE: Yeasts CANNOT express foreign, eukaryotic genes.

False

If DNA ligase were NOT used in the creation of a recombinant plasmid, __________. A. hydrogen bonds between complementary bases could not form B. the bacterium to receive the recombinant plasmid would not be competent and thus would be unable to take up the plasmid C. base-pairing would occur but the sugar phosphate backbone would not be connected D. links between guanine and cytosine would not occur E. links between adenine and thymine would not occur

C. base-pairing would occur but the sugar phosphate backbone would not be connected

To express a human gene in a bacterium, cDNA must be made because bacteria __________. A. splice RNA B. have reverse transcriptase C. cannot remove introns D. usually destroy human DNA

C. cannot remove introns

Which one of the following is a method of vertical gene transmission? A. transformation B. transduction C. cell division D. conjugation

C. cell division

E. coli may pick up a recombinant plasmid from a neighboring E. coli cell by __________. A. transduction B. transformation C. conjugation D. protoplast fusion

C. conjugation

Most amino acids are encoded by several different codons. This is referred to as the __________ of the genetic code. A. semi-conservativeness B. polarity C. degeneracy D. complementation

C. degeneracy

An ampicillin-sensitive culture of E. coli is transformed with a plasmid that contains the gene of interest plus an ampicillin-resistant gene. If it is then plated on an ampicillin-containing growth medium, __________. A. only the ampicillin-sensitive bacteria will grow B. only the lactose-positive bacteria will grow C. only the bacteria with the plasmid will grow D. no bacteria will grow E. all gram-negative bacteria will grow

C. only the bacteria with the plasmid will grow

If DNA ligase were NOT used in the creation of a recombinant plasmid, __________. A. hydrogen bonds between complementary bases could not form B. links between guanine and cytosine would not occur C. links between adenine and thymine would not occur D. the bacterium to receive the recombinant plasmid would not be competent and thus would be unable to take up the plasmid E. base-pairing would occur but the sugar phosphate backbone would not be connected

E. base-pairing would occur but the sugar phosphate backbone would not be connected

Recombinant DNA technology is used for all of the following EXCEPT __________. A. human insulin production by bacterial cells B. hepatitis B vaccine production using yeast cells C. insertion of genes from humans or plants into bacteria or viruses D. amplification of DNA for microbe identification E. culturing unknown organisms

E. culturing unknown organisms

Which of the following is an example of a cloning vector? A. ribosomal RNA B. mosquito C. rodent D. human growth hormone E. plasmid

E. plasmid

Recombinant DNA can be introduced into a host cell by any of the following methods EXCEPT __________. A. electroporation B. transformation C. microinjection D. protoplast fusion E. polymerase chain reaction

E. polymerase chain reaction

When the antibiotic chloramphenicol binds to the 50S portion of the ribosome, the effect is to __________. A. prevent transcription B. prevent tRNAs from binding to amino acids C. prevent RNA processing D. prevent peptide bond formation E. prevent the ribosome from moving along the mRNA strand

E. prevent the ribosome from moving along the mRNA strand

Which of the following processes is involved in the production of diphtheria toxin by C. diphtheria or erythrogenic toxin by Streptococcus pyogenes? A. conjugation B. transformation C. generalized transduction D. mutation E. specialized transduction

E. specialized transduction

Genetic technology has enabled screening for a variety of genetic conditions, and use of this technology is becoming more widely available. Which of the following is likely to become an important issue that will need to be addressed? A. the alteration of human phenotypes to prevent early disease B. the use of DNA analysis in anthropological studies C. the need for legislation to protect the privacy of individuals' genetic information D. the use of DNA analysis in criminal investigations

C. the need for legislation to protect the privacy of individuals' genetic information

Which of these statements is true about transduction? A. Bacteria-bacteria contact is required. B. A virus is required for transfer of genetic material. C. Naked DNA is passed from bacterium to bacterium. D. Segments of DNA move from one region of DNA to another. E. Genetic recombination does not occur.

B. A virus is required for transfer of genetic material.

Which of the following hypotheses was developed following Griffith's 1928 experiment? A. Streptococcus pneumoniae causes disease. B. DNA from dead encapsulated bacteria can transform living nonencapsulated bacteria into living encapsulated bacteria. C. Some pathogenic bacteria cannot be heat-killed. Bacterial virulence is related to temperature resistance. D. Dead encapsulated bacteria can cause disease.

B. DNA from dead encapsulated bacteria can transform living nonencapsulated bacteria into living encapsulated bacteria.

Which of the following attaches the target gene to a desired location? A. Restriction enzymes B. DNA ligase C. Plasmids D. Chromosomal DNA

B. DNA ligase

Which of the following might specifically be used as part of a reverse-genetics approach to studying a gene? A. Southern blotting B. RNA interference C. PCR D. reverse transcriptase E. Ti plasmid

B. RNA interference

A culture of identical cells, each derived from a single "parental cell," is referred to as a(n) __________.

Clone

Which of these statements is true for restriction enzymes? A. Any restriction enzyme can cut any piece of DNA. B. Restriction enzymes are useful in genetic engineering when they make staggered cuts in DNA. C. A different restriction enzyme must be used to open the vector DNA than to excise the gene sequence to be cloned. D. A given restriction enzyme will always recognize the same DNA sequence, but it will cut differently depending on the species of origin of the DNA. E. Each restriction enzyme is able to make a staggered cut at its recognition site

B. Restriction enzymes are useful in genetic engineering when they make staggered cuts in DNA.

Which of these answers is NOT true for positive (direct) selection? A. The selective medium is designed so that only the mutant cells grow on that medium. B. The procedure detects altered genotypes regardless of the phenotype. C. An example would be the detection of bacteria resistant to ampicillin by incorporation of ampicillin into the plating medium. D. It enables detection of a rare mutant from a population containing an extremely large number of bacteria. E. The mutant will grow on the selective medium, so there is no need for replica plating.

B. The procedure detects altered genotypes regardless of the phenotype.

How do restriction enzymes cut DNA sequences? A. They cut DNA at sequences that have lots of adenine bases. B. They cut DNA at sites, called recognition sites, that have specific nucleotide sequences. C. They have the ability to cut DNA randomly.

B. They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.

You are analyzing a segment of DNA and observe an area of sequence that appears to act as a promoter element. Based on this, what can you conclude? A. You have found the end of a gene. B. You have found the beginning of a gene. C. You have found an anticodon. D. You have found a place where DNA replication begins.

B. You have found the beginning of a gene.

A mutation occurs that results in a codon change from UGU to UGA. UGU encodes a cysteine amino acid, and UGA is a stop codon. Therefore, this is an example of __________. A. a transposon B. a nonsense mutation C. a missense mutation D. a frameshift mutation

B. a nonsense mutation

The tryptophan operon contains genes that encode the enzymes involved in tryptophan biosynthesis. An abundance of tryptophan will turn off the operon. This operon is an example of __________. A. a transformable operon B. a repressible operon C. an inducible operon D. a constitutive operon

B. a repressible operon

Assume you insert a specific gene into a plasmid and use blue-white screening. You plate the transformed E. coli cells on an ampicillin X-gal medium. Cells that produce blue colonies are __________. A. ampicillin sensitive and can hydrolyze X-gal B. ampicillin resistant but do not contain the new gene C. ampicillin sensitive and cannot hydrolyze X-gal D. ampicillin resistant and contain the gene of interest

B. ampicillin resistant but do not contain the new gene

The process of making multiple copies of a DNA molecule is referred to as __________. A. transformation B. amplification C. biomagnification D. hybridization E. protoplast fusion

B. amplification

cDNA is made from__________. A. a protein template B. an mRNA template C. a ribosomal DNA template D. a vector template

B. an mRNA template

Which of the following is a DNA strand complementary to 5' CGAATCA 3'? A. 3'GCAATGT5' B. 3'CGAATCA5' C. 5'GCUUAGU3' D. 3'GCTTAGT5'

D. 3'GCTTAGT5'

If you insert the gene for Bt toxin from Bacillus thuringiensis into a tomato plant, the resulting plants will __________. A. die B. be toxic to insects that eat them C. have a Bacillus infection D. be toxic to humans who eat the tomatoes

B. be toxic to insects that eat them

Recombinant DNA technology is used for all of the following EXCEPT ________. A. hepatitis-B-vaccine production using yeast cells B. culturing unknown organisms C. amplification of DNA for microbe identification D. human-insulin production by bacterial cells E. insertion of genes from humans or plants into bacteria or viruses

B. culturing unknown organisms

In nature, the function of restriction enzymes is to __________. A. cut plasmids B. destroy bacteriophage DNA C. destroy foreign DNA in animal cells D. splice DNA in a cel

B. destroy bacteriophage DNA

Which of these statements is true about transduction? A. Naked DNA is passed from bacterium to bacterium. B. Recombination does not occur. C. Segments of DNA move from one region of DNA to another. D. A virus is required for transfer of genetic material. E. Bacterium-bacterium contact is required.

D. A virus is required for transfer of genetic material.

For Agrobacterium tumefaciens to be used to introduce foreign DNA into a plant cell, that DNA must first be __________. A. inserted into the main chromosome of A. tumefaciens B. inserted into the T-DNA region of the Ti plasmid of A. tumefaciens C. isolated from the crown gall using the appropriate restriction enzyme D. inserted into the Ti plasmid of A. tumefaciens outside the T-DNA region E. inserted in an A. tumefaciens plasmid other than the Ti plasmid

B. inserted into the T-DNA region of the Ti plasmid of A. tumefaciens

In genetic engineering, antibiotic resistance genes are often cloned into a vector to __________. A. kill bacteria B. make direct selection of a clone possible C. select for cells that cannot grow D. enhance survival of the cloned cell

B. make direct selection of a clone possible

Which of the following is NOT an advantage of obtaining the protein product human growth hormone by recombinant DNA technology rather than extraction from cadavers? A. elimination of the need to extract the protein from tissues that might harbor pathogens B. production of endotoxins C. purity D. speed E. cost-effectiveness

B. production of endotoxins

Which of the following is NOT a purpose of genetic modification? A. modification of the characteristics of an organism B. removal of antibiotic-resistant plasmids from bacteria C. creation of multiple copies of a gene of interest D. creation of hormones such as insulin or human growth hormone E. creation of proteins used in vaccines (e.g., hepatitis B vaccine)

B. removal of antibiotic-resistant plasmids from bacteria

The shotgun sequencing technique is used to __________. A. locate genes B. sequence entire genomes C. cut chromosomes into fragments D. make an artificial chromosome

B. sequence entire genomes

The Ames test is used __________. A. to verify that a chemical is mutagenic B. to determine if a chemical is mutagenic and possibly carcinogenic C. to determine the carbohydrate requirements of gram-negative bacteria D. to determine if bacteria develop cancer E. to determine if Salmonella can use the amino acid histidine

B. to determine if a chemical is mutagenic and possibly carcinogenic

The basic steps to genetically modify a cell are listed below. Which step would come LAST? A. restriction digestion of vector B. transformation C. ligation D. restriction digestion of gene

B. transformation

Your lab partner has mixed a dead tryptophan+ strain of Bacillus subtilis with a live tryptophan- strain and observes that her B. subtilis culture is now tryptophan+. The most likely explanation for this is __________. A. conjugation B. transformation C. specialized transduction D. generalized transduction E. mutation

B. transformation

All of the following are benefits and improvements made possible by recombinant DNA technology EXCEPT __________. A. improved weed and pest control B. use of baker's yeast to produce bread C. development of genetic screening procedures for early detection of genetic diseases D. development of new, safer vaccines

B. use of baker's yeast to produce bread

Auxotrophs __________. A. cannot be separated from nonmutants in a population, because both can grow on a complete medium that contains the growth factor B. will not grow on a plate that lacks the growth factor, but will grow on a complete medium that contains the growth factor C. are mutants that can synthesize a nutrient the parent cannot D. can be isolated by direct selection E. will not grow on a complete medium that contains the growth factor, but will grow on a plate that lacks the growth factor

B. will not grow on a plate that lacks the growth factor, but will grow on a complete medium that contains the growth factor

What is the temperature used for the extension step? A. 94 °C B. 60 °C C. 72 °C

C. 72 °C

What is the sequence of the temperatures of a typical PCR reaction? A. 94 °C, 72 °C, 60 °C B. 72 °C, 94 °C, 60 °C C. 94 °C, 60 °C, 72 °C D. 60 °C, 72 °C, 94 °C E. 72 °C, 60 °C, 94 °C

C. 94 °C, 60 °C, 72 °C

Consider the polypeptide sequence encoded by the following DNA: 3'TACAAAGAAATT5' If base number 6 is changed to G, how will this affect the polypeptide? A. A frameshift mutation will result. B. One amino acid will be changed. C. There will be no change in the polypeptide. D. A nonsense mutation will result in premature termination of the polypeptide. E. Translation will stop.

C. There will be no change in the polypeptide.

Which of the following best describes a clone in the context of genetic modification procedures? A. an identical copy of the gene of interest B. a vector, once it contains a copy of the gene of interest C. a culture of genetically identical cells D. a cell that is genetically identical to its parent

C. a culture of genetically identical cells

Which of the following can cause changes in a sequence of several amino acids? A. a base substitution B. a nonsense mutation C. a frameshift mutation D. a missense mutation

C. a frameshift mutation

Which of the following is NOT a step in Southern blotting? A. addition of a radioactive probe made from the gene of interest B. digestion of sample DNA with restriction enzyme C. addition of heat-stable DNA polymerase D. transfer of DNA fragments to filters E. separation of DNA fragments by gel electrophoresis

C. addition of heat-stable DNA polymerase

When two DNA pieces cut with the same restriction enzyme are combined, sticky ends will __________. A. associate by covalent bonds B. not associate C. associate by complementary base pairing and hydrogen bonds D. associate only if they are double-stranded E. associate because of DNA ligase

C. associate by complementary base pairing and hydrogen bonds

The transfer of genetic information between organisms through processes such as transduction or conjugation is called ______ gene transfer

Horizontal

_______ is a technique used to quickly amplify specific sequences of DNA.

Polymerase chain reaction

____________, useful in recombinant DNA technology, are bacterial enzymes that recognize and cut specific sequences of DNA.

Restriction Enzymes

Plasmids that can exist in disparate species such as a bacterium and a plant cell are called ________ vectors, and they can be used to transfer cloned DNA from one type of organism to another.

Shuttle

TRUE OR FALSE: If a foreign gene inserted into a plasmid inactivates the β-galactosidase gene, a bacterium containing that plasmid would form blue colonies on X-gal medium.

True

TRUE OR FALSE: In prokaryotes, translation of an mRNA molecule can begin before transcription of the mRNA molecule is completed.

True

TRUE OR FALSE: RNA interference (RNAi) can be used to silence a gene, and it holds promise for treating certain genetic disorders and viral infections.

True

TRUE OR FALSE: When bacteria are genetically modified to produce a protein product, technical difficulties arise because that product is NOT always secreted from the cell.

True

TRUE OR FALSE: codons of mRNA temporarily bond to anticodons of tRNA during translation.

True

Genes whose products are produced constantly are known as ______ genes.

constitutive

To begin transcription, the RNA polymerase binds a region on DNA known as the ___________.

promoter

The introduction of external pieces of "naked" DNA from solution into a cell is referred to as _________.

transformation

Small stretches of DNA that can move within a genome are referred to as ________.

transposons

The following steps are necessary to clone eukaryotic genes in bacteria. What is the third step? A. reverse transcription of mRNA B. splice exons together C. remove introns D. transcription

B. splice exons together

Which of the following is NOT a step in translation? A. peptide bond formation B. initiation at the AUG start codon C. joining of the Okazaki fragments D. transport of amino acids by tRNAs E. pairing of codons with anticodons

C. joining of the Okazaki fragments

Which of the following can be used as vectors to genetically modify cells? A. shuttle vectors B. viruses C. plasmids D. all of these

D. all of these

TRUE OR FALSE: Hfr cells transfer genes to recipient cells in a particular order.

True

For the peptide with the amino acid sequence, proline-alanine-glycine (pro-ala-gly), the DNA template strand could have the sequence __________. A. 3'GGC CGA CCG5' B. 3'CGC GCC GGA5' C. 3'CCG GCC GGG5' D. 3'GGU CGA CCA5' E. 3'CCU GCC GGC5'

A. 3'GGC CGA CCG5'

Use the genetic code in your textbook (Figure 8.8) to solve this problem: The mRNA copied from a given gene is as follows: 5'UACAAAGAAAUU3'. If base 2 were changed to U, what effect would this have? A. A missense mutation would occur. A frameshift mutation will result. A nonsense mutation will occur. Transcription would stop.

A. A missense mutation would occur.

Which of the following best describes how recombinant DNA technology currently helps patients who do NOT produce adequate amounts of growth hormone (hGH)—a condition that otherwise leads to stunted growth? A. Bacteria now produce hGH. B. Bacteria now produce rDNA coding for hGH. C. Recombinant vectors now produce hGH. D. Recombinant vectors are used to stimulate hGH production in these patients.

A. Bacteria now produce hGH.

Which of the following statements correctly differentiates biotechnology from rDNA technology? A. Biotechnology involves any use of microorganisms or cells to make products, regardless of the means used. Recombinant DNA technology involves methods for handling and modifying DNA and inserting it into different types of cells. B. Biotechnology includes genetic modification of eukaryotic cells and prokaryotic cells, whereas rDNA technology exclusively involves the genetic modification of bacteria. C. Biotechnology includes techniques for gene amplification, whereas rDNA technology includes techniques for altering the nucleotide sequence of an organism's DNA. D. Biotechnology is concerned only with the production of recombinant proteins, whereas rDNA technology is concerned exclusively with DNA.

A. Biotechnology involves any use of microorganisms or cells to make products, regardless of the means used. Recombinant DNA technology involves methods for handling and modifying DNA and inserting it into different types of cells.

Which of the following statements correctly differentiates biotechnology and rDNA technology? A. Biotechnology involves any use of microorganisms or cells to make products, regardless of the means used. rDNA technology involves the specific use of molecular modifications in microorganisms or cells, in which a gene from one cell is inserted into another cell, altering the recipient cell to make some desired product. B. Biotechnology includes genetic modification of eukaryotic cells and prokaryotic cells, whereas rDNA technology exclusively involves the genetic modification of bacteria. C. Biotechnology includes techniques for gene amplification, whereas rDNA technology includes techniques for altering the nucleotide sequence of an organism's DNA. D. Biotechnology is concerned only with the production of proteins, whereas rDNA technology is concerned exclusively with DNA.

A. Biotechnology involves any use of microorganisms or cells to make products, regardless of the means used. rDNA technology involves the specific use of molecular modifications in microorganisms or cells, in which a gene from one cell is inserted into another cell, altering the recipient cell to make some desired product. B. Biotec

DNA fingerprints are actually __________. A. DNA fragments B. genes C. RNA D. cDNA

A. DNA fragments

Of the choices below, which is the LAST to happen during DNA replication? A. DNA ligase joins all the new pieces together. B. Primase synthesizes primers for each strand. C. Primers are removed and replaced with DNA. E. The two template strands of DNA are unwound.

A. DNA ligase joins all the new pieces together.

In a laboratory setting, which of the following scenarios would benefit from utilizing a technique such as PCR? Select all that apply. A. You want to study the effects of a protein on different cell types, but the bacterial species that the protein originates from is considered a pathogen. B. You would like to make copies of a bacterial gene of interest for sequencing and characterization. C. You have a fastidious organism that is hard to grow in large numbers and you need to isolate an operon for transferring to a bacterium for expression. D. You need to amplify an entire bacterial chromosome to characterize the genes present.

A. You want to study the effects of a protein on different cell types, but the bacterial species that the protein originates from is considered a pathogen. B. You would like to make copies of a bacterial gene of interest for sequencing and characterization. C. You have a fastidious organism that is hard to grow in large numbers and you need to isolate an operon for transferring to a bacterium for expression.

Cells will not express genes that are on DNA fragments floating in their cytoplasm. To express the genes on such a fragment, you will need a vector, a DNA construct that will deliver your genes into the new cell and will have the necessary DNA promoter sequences to initiate transcription. The vector that will suit your needs for this project is an expression plasmid. A plasmid is a small circular strand of a DNA double helix that will have a site for insertion of your DNA fragment and the necessary promoters for expression of the genes. The sequence of the circular plasmid will be digested with the same restriction enzyme you used to cut out the fragment from the bacterial chromosome. The fragment will then be fused into the opened plasmid using the enzyme DNA ligase. The ends of the fragment will be paired with the cut ends of the plasmid based on DNA nucleotide sequences. Since the same enzyme was used to cut the fragment and the plasmid, this will result in the ends having identical DNA base sequences, which repair enzymes will recognize and ligate the DNA sequences together. The question now is which plasmid of the hundreds of commercially available plasmids you should use.Which plasmid characteristics would be required for optimal expression of a DNA fragment to yield a peptide? Choose all that apply. A. a region with multiple sites for restriction digestion with different enzymes B. a DNA sequence that signals for trafficking of the plasmid to the nucleus C. a strong promoter for expression of the inserted DNA fragment D. a sequence for insertion of the expressed protein into the cell wall

A. a region with multiple sites for restriction digestion with different enzymes B. a DNA sequence that signals for trafficking of the plasmid to the nucleus C. a strong promoter for expression of the inserted DNA fragment

For the introduction of a genetically modified plasmid into E. coli, __________. A. calcium chloride and heat shock can be used B. protoplast fusion must be used C. microinjection must be used D. a gene gun must be used E. no treatment is needed, because the cells are naturally competent

A. calcium chloride and heat shock can be used

Which one of the following is a method of vertical gene transfer? A. cell division B. transduction C. transformation D. conjunction

A. cell division

Which of the following requires cell-to-cell contact? A. conjugation B. transduction C. mutation D. transformation

A. conjugation

Which of the following is NOT an advantage of obtaining the protein product called human growth hormone by recombinant DNA technology rather than extraction from cadavers? A. production of endotoxins B. purity C. cross contamination D. cost-effectiveness E. speed

A. production of endotoxins

The antibiotic kasugamycin blocks binding of bacterial tRNA that carries formylmethionine to a ribosome. From this information, you can conclude that kasugamycin prevents __________. A. protein synthesis B. DNA replication C. conjugation D. gene transcription

A. protein synthesis

Both transcription and DNA replication involve __________. A. synthesis using a DNA template B. formation of molecules containing the same number of nucleotides as the parent chromosome C. synthesis of molecules containing the nitrogenous base thymine D. synthesis of molecules containing the sugar deoxyribose E. formation of polymers of amino acids

A. synthesis using a DNA template

Sequencing a genome directly provides __________. A. the order of nucleotides in a genome B. restriction fragments C. a gene sequence D. identity of proteins expressed by the cell

A. the order of nucleotides in a genome

If a recombinant plasmid is put in solution with E. coli, the bacteria may pick up the plasmid by __________. A. transformation B. transduction C. protoplast fusion D. conjugation

A. transformation

Which of the following statements correctly differentiates a genomic library from a cDNA library? A. Genomic libraries contain only those genes that a cell is currently expressing, whereas cDNA libraries contain all of the cell's genes, whether expressed or not. B. A genomic library contains only noncoding DNA sequences, whereas a cDNA library contains only coding sequences C. A genomic library contains fragments of the entire DNA in an organism's genome. A cDNA library contains the coding sequences of eukaryotic genes (minus the introns). D. Genomic libraries are prepared from eukaryotes, and cDNA libraries are prepared from prokaryotes. E. cDNA libraries can be used for sequencing, but they cannot be transcribed and translated. Genomic libraries can be used for sequencing and for production of the desired protein product.

C. A genomic library contains fragments of the entire DNA in an organism's genome. A cDNA library contains the coding sequences of eukaryotic genes (minus the introns).

Which one of the following nucleotide sequences is most likely affected by ultraviolet light? A. TATATA B. GACACC C. AGTTTC D. GATCGG

C. AGTTTC

Which of the following best describes why a vector is used in genetic modification procedures? A. The vector ensures that the clone remains pure. B. The clone must be able to produce proteins from the rDNA containing the gene of interest. C. Cells usually won't copy an isolated gene sequence. D. The gene of interest must be isolated from adjacent genes.

C. Cells usually won't copy an isolated gene sequence.

With your fragment now in an expression plasmid, you will need to check to ensure that the fragment is in the correct reading frame from the promoter so that a functional enzyme can be made. You will utilize the polymerase chain reaction (PCR) to amplify a section of the plasmid containing your insert so that it can be sequenced. PCR uses a DNA polymerase isolated from a hyperthermophilic bacterial species to synthesize a new DNA strand off a template strand of DNA. You are supplying a template in the form of the plasmid with the inserted fragment. PCR also uses the requirement of DNA polymerase to have a pre-existing primer with an open 3' end for new strand synthesis. You will provide the primers that will bind to specific DNA sequences before and after the inserted fragment and will act as boundaries for what part of the plasmid will be amplified. The resulting short, amplified fragments will be identical in base sequence to the original plasmid templates. Once PCR amplification is complete, you will have enough template fragments to send for DNA sequencing to ensure that you have inserted the genes correctly into the plasmid. Correct insertion will result in the production of an mRNA strand that will have the first gene codon in the correct reading frame for a working enzyme to be produced.Of the following components, which ones are required for the amplification of a specific section of DNA using the polymerase chain reaction? Select all that apply. A. RNA polymerase B. a strand of RNA to act as a template C. DNA primers D. DNA polymerase that is heat stable

C. DNA primers D. DNA polymerase that is heat stable

Which of these statements is NOT true of translation? A. The "language" of nucleotides is changed to the "language" of amino acids. B. A single mRNA may have several ribosomes attached. C. Each amino acid is coded for by a single codon. D. Three different nonsense codons code for termination of protein synthesis. E. A molecule of tRNA can bind to both an mRNA molecule and an amino acid.

C. Each amino acid is coded for by a single codon.

The following sequential steps are used to make a recombinant cell. Which of these steps occurs LAST? A. Insert gene into a vector. B. Vector is taken up by cell. C. Grow cells containing vector with the gene of interest. D. Isolate gene of interest

C. Grow cells containing vector with the gene of interest.

Which one of the following would be the most likely to yield a recombinant cell after mating? A. Hfr cell transfers to F+ cell. B. F- cell tranfers to Hfr cell C. Hfr cell transfers to F- cell. D. F- cell transfers to F+ cell.

C. Hfr cell transfers to F- cell.

Which of the following is NOT true of the polymerase chain reaction (PCR)? A. A heat-stable DNA polymerase is used in the reaction process. B. Short pieces of DNA called primers are added to the reaction mixtures. C. Large amounts of DNA must be isolated from the source organism. D. Billions of copies of a DNA sequence are made in a few hours. E. An automated thermocycler is used to heat and cool the reaction samples.

C. Large amounts of DNA must be isolated from the source organism.

Which of the following statements about DNA replication is FALSE? A. Primase synthesizes the primers. B. DNA ligase joins the small DNA fragments of the lagging strand. C. Only one strand of the parent DNA serves as a template for a newly synthesized complementary strand. D. DNA polymerase is required to add new nucleotides to the growing ends of the DNA strands.

C. Only one strand of the parent DNA serves as a template for a newly synthesized complementary strand.

Recombinant DNA techniques typically involve generating a clone. Why? A. A clone is used to get the gene of interest into a suitable cell. B. A clone is generated when a cell takes up the vector. C. Producing a clone generates many copies of the gene of interest. D. Recombining the clone produces the recombinant DNA.

C. Producing a clone generates many copies of the gene of interest.

During conjugation, DNA is transferred from one bacterium to another. Often, it is plasmid DNA that is transferred. Which of the following plasmid names correctly matches the information that it carries? A. dissimilation factors—antibiotic-resistance genes B. R factor—fertility factor C. R factors—antibiotic-resistance genes D. F factor—plasmids that carry antibiotic resistance

C. R factors—antibiotic-resistance genes

Which of the following enzymes and their function are MISMATCHED? A. DNA helicase—unwinds two strands of DNA B. DNA ligase—joins pieces of DNA together C. RNA polymerase—makes DNA D. DNA polymerase—synthesizes DNA and proofreads

C. RNA polymerase—makes DNA

What is a thermocycler? A. The process of cycling through the different temperatures of a PCR reaction 30 times B. The name for the DNA primers used in a PCR reaction C. The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR D. The special DNA polymerase, used in a PCR reaction, that can tolerate the high temperatures

C. The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR

You have to this point cut out your genes of interest, inserted them into an expression plasmid, amplified the section of the plasmid carrying the genes, and sequenced them to check for proper insertion. Now you have to get the plasmid into the yeast cell to see whether yeast can express the new bacterial proteins. You could just add the plasmid to a yeast culture and some cells would eventually take up the plasmid on their own. This would be extremely inefficient, though, and would result in very few transformed cells in a population numbering in the millions. You need a technique that will allow for many--if not all--of the cells to take up the plasmid, thus increasing your chances of finding a cell that can successfully express a gene off of the plasmid. One way to do this would be via electroporation. In electroporation, you will place a sample of cells in an electrical field suspended in a salt solution. This combination will trigger all of the ion-gated channels on the cytoplasmic membrane of the cell to be opened at once. The opened channels will allow for an influx of fluid into cells containing the plasmid.In an effort to yield a high percentage of transformed bacteria, you may choose to utilize electroporation to increase the probability of what occurring? A. The plasmid requires an electoral field to be activated for use by the bacterial cell. B. that a few of the cells will be able to take up the expression plasmid C. that the cells will be active and have the ability to take up the plasmid D. that nearly all of the cells present in the field will take up at least one copy of the plasmid

D. that nearly all of the cells present in the field will take up at least one copy of the plasmid

What is the purpose of DNA replication? A. to make an RNA molecule B. to synthesize a protein C. to generate mutations D. to make an identical copy of DNA

D. to make an identical copy of DNA

Which means of genetic transfer among bacteria involves a virus? A. transformation B. mutation C. conjugation D. transduction

D. transduction